[PATCH] firmware: arm_scmi: fix i.MX build dependency

[Arnd Bergmann <arnd@xxxxxxxxxx>]

From: Arnd Bergmann <arnd@xxxxxxxx>

The newly added SCMI vendor driver references functions in the
protocol driver but needs a Kconfig dependency to ensure it can link,
essentially the Kconfig dependency needs to be reversed to match the
link time dependency:

arm-linux-gnueabi-ld: sound/soc/fsl/fsl_mqs.o: in function `fsl_mqs_sm_write':
fsl_mqs.c:(.text+0x1aa): undefined reference to `scmi_imx_misc_ctrl_set'
arm-linux-gnueabi-ld: sound/soc/fsl/fsl_mqs.o: in function `fsl_mqs_sm_read':
fsl_mqs.c:(.text+0x1ee): undefined reference to `scmi_imx_misc_ctrl_get'

This however only works after changing the dependency in the SND_SOC_FSL_MQS
driver as well, which uses 'select IMX_SCMI_MISC_DRV' to turn on a
driver it depends on. This is generally a bad idea, so the best solution
is to change that into a dependency.

To allow the ASoC driver to keep building with the SCMI support, this
needs to be an optional dependency that enforces the link-time
dependency if IMX_SCMI_MISC_DRV is a loadable module but not
depend on it if that is disabled.

Fixes: 61c9f03e22fc ("firmware: arm_scmi: Add initial support for i.MX MISC protocol")
Fixes: 101c9023594a ("ASoC: fsl_mqs: Support accessing registers by scmi interface")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
I'm not sure this is the version we want to go with in the end, without
having read the code in detail, but the version in linux-next is clearly
wrong in multiple ways and this is the best I could come up with so far.

If we can agree on this approach, it needs to go through the ASoC tree
as that contains the 101c9023594a commit at the moment.
---
 drivers/firmware/arm_scmi/vendors/imx/Kconfig | 1 +
 drivers/firmware/imx/Kconfig                  | 1 -
 sound/soc/fsl/Kconfig                         | 2 +-
 3 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/arm_scmi/vendors/imx/Kconfig b/drivers/firmware/arm_scmi/vendors/imx/Kconfig
index 2883ed24a84d..a01bf5e47301 100644
--- a/drivers/firmware/arm_scmi/vendors/imx/Kconfig
+++ b/drivers/firmware/arm_scmi/vendors/imx/Kconfig
@@ -15,6 +15,7 @@ config IMX_SCMI_BBM_EXT
 config IMX_SCMI_MISC_EXT
 	tristate "i.MX SCMI MISC EXTENSION"
 	depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF)
+	depends on IMX_SCMI_MISC_DRV
 	default y if ARCH_MXC
 	help
 	  This enables i.MX System MISC control logic such as gpio expander
diff --git a/drivers/firmware/imx/Kconfig b/drivers/firmware/imx/Kconfig
index 477d3f32d99a..907cd149c40a 100644
--- a/drivers/firmware/imx/Kconfig
+++ b/drivers/firmware/imx/Kconfig
@@ -25,7 +25,6 @@ config IMX_SCU
 
 config IMX_SCMI_MISC_DRV
 	tristate "IMX SCMI MISC Protocol driver"
-	depends on IMX_SCMI_MISC_EXT || COMPILE_TEST
 	default y if ARCH_MXC
 	help
 	  The System Controller Management Interface firmware (SCMI FW) is
diff --git a/sound/soc/fsl/Kconfig b/sound/soc/fsl/Kconfig
index 8e88830e8e57..678540b78280 100644
--- a/sound/soc/fsl/Kconfig
+++ b/sound/soc/fsl/Kconfig
@@ -29,8 +29,8 @@ config SND_SOC_FSL_SAI
 config SND_SOC_FSL_MQS
 	tristate "Medium Quality Sound (MQS) module support"
 	depends on SND_SOC_FSL_SAI
+	depends on IMX_SCMI_MISC_DRV || !IMX_SCMI_MISC_DRV
 	select REGMAP_MMIO
-	select IMX_SCMI_MISC_DRV if IMX_SCMI_MISC_EXT !=n
 	help
 	  Say Y if you want to add Medium Quality Sound (MQS)
 	  support for the Freescale CPUs.
-- 
2.39.5